Area Forecast Discussion
Issued by NWS Memphis, TN
Issued by NWS Memphis, TN
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
549 FXUS64 KMEG 242026 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 326 PM CDT Tue Sep 24 2024 ...New SYNOPSIS, DISCUSSION... .SYNOPSIS... Issued at 326 PM CDT Tue Sep 24 2024 An unsettled weather pattern will prevail across the Midsouth during the middle and late portions of the week. A deep upper level low pressure system will move into the Midsouth on Wednesday, and move only little through Saturday. This upper low will bring a rainfall into the upcoming weekend, aided by moisture from the remnants of what will likely become Hurricane Helene. High temperatures will prevail in the 70s Wednesday through Saturday. && .DISCUSSION... (This evening through next Monday) Issued at 326 PM CDT Tue Sep 24 2024 Mid-afternoon GOES water vapor imagery showed a closed upper low developing over the MO River Valley. A belt of strong southwest flow aloft was evident southwest of the low, extending from southern AR through the OH River Valley. SPC Mesoanalysis indicated 45 knots of effective bulk shear across northeast MS, coincident with 2500 J/kg of mixed layer CAPE. A Marginal severe threat will continue across the northeast MS into portions of southern west TN into early evening, before CINH increases and upper level divergence zone shifts east into AL. Tropical Storm Helene is forecast to intensify into a major hurricane on Thursday, before making landfall over the FL panhandle Thursday evening. Thereafter, Helene will make a fairly quick path through the Southeast, aided by southerly flow ahead of the synoptic closed low over the Midsouth. Helene`s remnant low will weaken after passing through the southern Appalachians. But the remnant low and tropical moisture will become entrained into the northern side of the synoptic low by Thursday night. PWAT values near 2 inches and the potential for training will result in a Slight Risk for excessive rainfall over west TN and northeast MS late Thursday into early Friday. The synoptic low will weaken and lift into OH Valley on Sunday. Some light wrap-around showers will be possible Sunday and Monday, mainly to the north and east of Memphis. Thereafter, a northern branch trough will drop from the Canadian prairie into the Great Lakes. There remains some spread in global models with respect to the amplitude of this trough and resultant northwest flow across the Midsouth. But at this time, there appears to be a better than even chance of a cold frontal passage around the middle of next week. Autumn-like dewpoints in the 40s and 50s may be on the horizon. PWB && .AVIATION... (18Z TAFS) Issued at 1220 PM CDT Tue Sep 24 2024 Current satellite imagery shows a trough digging through the region this morning with associated clouds. So far, only intermittent drops to MVFR have been seen across E AR. Have included FEW025 to account for any drops into MVFR at JBR/MEM through 00z. Otherwise, the most notable impact through this afternoon will be TS in the vicinity of MKL/TUP. A cold front is currently in E AR and will continue eastward throughout the period with storms forming along it. Convection is expected to persist in the region through at least 22z up until 00z this evening. Overnight, clouds should generally lower in coverage before post- frontal CIGs at 10 kft overspread the region. Some visibility drops are possible in MKL, so kept 4 SM for now with changes being possible in subsequent TAFs. Otherwise, VFR is likely to prevail for much of the remainder of the period at all sites with a clearing trend through tomorrow. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...PWB AVIATION...JAB